1. Field of the Invention
The present invention relates to electrical connector receptacles, more particularly to an electrical connector receptacle suitable for a modular connector for telephone sets or measuring instruments, and a process for manufacturing the same.
2. Description of the Prior Art
In recent years, a growing number of small and inexpensive modular connectors are used for telephone sets, measuring instruments, or minicomputers. For example, Japanese Patent Kokai No. 55-37,800 discloses a modular connector of such a type. As FIGS. 15 and 16 show, this modular connector consists of a connector receptacle 10 and a connector plug 20. An insulating housing 11 of receptacle 10 is made of plastic and has a post 13 for mounting on a circuit board 30. The insulating housing 11 has a plug-receiving end 11A, a rear end 11B, and a plug-receiving opening 12 extending from the plug-receiving end toward the rear end. The plug-receiving opening 12 is defined by upper and lower internal walls 12A and 12B and opposite internal side walls 12C. The insulating housing has upper and lower external walls 13A and 13B and opposite external side walls 13C. The lower external wall is provided integrally with a post 13 for mounting the connector receptacle 13 on the circuit board 30 by inserting the post into a hole of the circuit board. A plurality of parallel recesses 14 are provided between upper internal and external walls 12B and 13B and communicate with a plurality of parallel channels 15 provided on upper external wall 13B. A plurality of parallel barriers 15A are provided between channels 15 and extend beyond rear end 11B and downward to lower external wall 13A. A pair of retainer surfaces 16 are provided in plug-receiving opening 12. A plurality of parallel contacts 17 are arranged within housing 11. Each contact has an elongated intermediate portion 17A extending across upper external wall 13B and bent downward at 17B. The intermediate portion 17A has a tail portion 17C extending downward across rearward end 11B. The spring portion 17D of each contact 17 extends diagonally from the bent portion 17B within the recess 14 toward the plug-receiving opening 12. The free end of tail 17C of each contact 17 protrudes from lower external wall 13A for soldering to the conductor of circuit board 30. A central recess 18 is provided at the center of lower internal wall 12A extending downward to plug-receiving end 11A. A pair of opposite shoulders are provided on both sides of central recess 18 giving retainer surfaces 16. These shoulders face toward the rear end 11B of housing 11 for engagement with the shoulders of a latch arm 21. As best shown in FIG. 16, when the plug 20 is inserted into the plug-receiving opening 12 of connector receptacle 10 mounted on the circuit board 30 until the shoulder of latch arm 21 engages the shoulders of the retainer 16, the spring portions 17D of individual contacts 17 come into electrical contact with the corresponding terminals 22 of plug 20.
U.S. Pat. No. 4,193,654 issued to Hughes et al. on Mar. 18, 1980, discloses substantially the same electrical connector receptacles as described above.
U.S. Pat. No. 4,202,593 issued to Abernethy et al. on May 13, 1980, discloses a telephone jack comprising a cover portion and a base portion. The base portion has a rectangular pillar with a plurality of vertically extending cavities and an integral platform with a clearance separating the platform and the bottom wall. The platform has a plurality of parallel grooves. Each elongated contact is inserted into the cavity through the bottom. Then, the contact is bent laterally at a first bend to follow along a corresponding groove of the platform. The contact is bent again at a second arcuate bend to follow along the groove in the arcuate end. A free end of each contact projects diagonally from the end into the clearance.
U.S. Pat. No. 4,210,376 issued to Huges et al. on Jul. 1, 1980, discloses an electrical connector receptacle comprises a one piece molded housing having a plug-receiving end, a plug-receiving opening extending toward the plug-receiving end, and a plurality of parallel channels in the upper external wall. A plurality of parallel contacts are mounted in the housing by positioning a section of the strip bent at right angles in the channel, with free ends adjacent to the shoulder, bending the spring portions inwardly into the plug-receiving opening, and bending the other end portions downward into the rear end channels.
However, these electrical connector receptacles have some of the following shortcomings:
The contacts extend upward across the rear wall and laterally along the upper external wall and bent inward below the upper internal wall thus surrounding the upper wall. Consequently, it is very hard to mount prefabricated contacts within the insulating housing. For this reason, the contacts must be bent into a desired shape after they are placed on the insulating housing. This is a very difficult operation without bending the soft plastic housing. Thus, such operation has been troublesome and time consuming, pushing up the connector price. In addition, the intermediate portion of each contact in the channel is exposed to the outside so that dirt and dust tend to accumulate on the contacts, causing troubles such as a short-circuit.